FDG PET/CT imaging in primary osseous and soft tissue sarcomas: a retrospective review of 212 cases

The aims of this study are to evaluate the sensitivity of FDG PET/CT for detection of soft tissue and osseous sarcomas on the basis of FDG avidity. We retrospectively evaluated 212 consecutive patients with known soft tissue or osseous sarcoma who had undergone a FDG PET/CT study for the initial staging or assessment of recurrence of disease. The maximum standardized uptake value (SUV(max)) of each primary and/or most intense metastatic lesion was measured and compared with the histological data provided in the final pathological reports. An SUV(max) of 2.5 or greater was considered positive for our analysis. Sufficient histopathological data were available for 160 soft tissue sarcomas and 52 osseous sarcomas. FDG PET/CT detected 93.9% of all sarcomas with a sensitivity of 93.7% for soft tissue sarcomas and 94.6% for osseous sarcomas. The sensitivities of the most common sarcoma histologies were 100% for leiomyosarcomas, 94.7% for osteosarcomas, 100% for Ewing's sarcomas, 88.9% for liposarcomas, 80.0% for synovial sarcomas, 100% for gastrointestinal stromal tumors, 87.5% for malignant peripheral nerve sheath tumors, 100% for fibroblastic and myoblastic sarcomas, and 100% for malignant fibrohistiocytic tumors. The receiver-operating characteristic curve revealed an area under the curve of 94% for the discrimination of low-grade and high-grade sarcomas imaged for initial staging by FDG PET/CT. The combined metabolic and morphological information of FDG PET/CT imaging allows high sensitivity for the detection of various sarcomas and accurate discrimination between newly diagnosed low-grade and high-grade sarcomas.